CERCLA Remedial Investigation (RI) includes which of the following?

• A. It focuses exclusively on budgetary constraints
• B. It conducts only noise surveys
• C. It does not involve risk assessment
• D. Investigators define the nature and extent of contamination at the site and conduct a baseline risk assessment

Answer: (D)

During a CERCLA Remedial Investigation, the core aim is to characterize the site by defining the nature and extent of contamination and to perform a baseline risk assessment to estimate the current risks to human health and the environment under existing conditions. This information shows what contaminants are present, where they are, and how much, and it quantifies the risk to determine what cleanup levels might be needed. The other ideas—focusing on budgetary constraints or conducting only noise surveys—don't capture the primary purpose of the RI, and risk assessment is an essential part of the RI rather than something to be omitted.